A wealth of evidence supports an association between regular physical activity (PA) and decreased risk for cancer and cancer mortality. This is clearly an important issue given the growing worldwide incidence of both cancer and physical inactivity. Of further importance is unraveling the biological mechanisms that explain the potential preventive effects of PA against the development of cancer, as this might improve our understanding of cancer biology and assist researchers exploring novel treatment strategies. Here we review mechanistic studies that help explain the anticancer effects of exercise based on how exercise impacts hallmark features of cancer. We also discuss the emerging role of myokines, methodological caveats in the field, and potential questions that remain to be addressed in future research.
Regular, moderate-intensity physical activity (PA) (e.g., brisk walking) decreases the risk of many cancers as well as of cancer mortality.
To a certain extent, PA’s benefits on cancer risk/mortality are dose dependent (e.g., even more evident in elite athletes), and no detrimental effect has been found.
In animal studies regular exercise inhibits tumor onset and progression across a wide range of tumor models and anatomical locations.
The usual schedule in animal models showing inhibition of cancer progression is regular exercise on most days of the week (up to 60 min/session) for several weeks (4–32 weeks, which translates into human ‘years’) using, typically, voluntary wheel running, but also forced treadmill running or swimming.